Bounded Wildcard

A wildcard restricted to types above or below a stated type in the hierarchy.

What is Bounded Wildcard in Java?

Bounded Wildcard — A wildcard restricted to types above or below a stated type in the hierarchy.

import java.util.List;

class NumberTotal {
    double total(List<? extends Number> values) {
        return values.stream()
                .mapToDouble(Number::doubleValue)
                .sum();
    }
}

Level: Freelancer · More Java terms at this level

Updated